I've had a cough for 3 months tried cogh meds didn't work got chest xrays came back fine its not from acid reflux either what else could i do to help.?

Medicines?: Some medications are known to cause chronic cough. Most common is ace inhibitor. However, a bronchoscope is needed along with pulminary function testing to rule out pathological cause that cxr misses and to make sure asthma is not the cause.

Sinuses? Reflux?: Why do you say it's not reflux? Cough that comes from reflux can be silent without any abdominal symptoms. It is also much harder to treat relying on strict diet control avoiding all acids, coffee, tea, sodas, etc... As well as not eating or drinking anything for 3 hours prior to laying down. In addition to proton pump inhibitor. It also could be chronic sinusitis. Have you had an ENT evaluation?